Sliding closure for pressure vessels and autoclaves



F. LINDER Nov. 18, 1969 SLIDING CLOSURE FOR PRESSURE VESSELS AND AUTOCLAVES Filed Oct. 1, 1968 INVENTOR Fm'r'z 'LINDER M kw; 4w

HTTOR/VYS United States Patent Int. Cl. B65d 43/12: 53/00; B01j 3/02 US. Cl. 220-41 9 Claims ABSTRACT OF THE DISCLOSURE The invention provides a closure for a pressure vessel, particularly an autoclave, fitted with a door, 'or with a similar closure resembling a door, comprising two plates jointly slida bly movable across the opening of the pressure vessel and forming an intermediate pressure chamber between them which is sealed in relation to the outside, said intermediate pressure chamber and the interior of said pressure vessel being in communication, and sealing means provided between the closure and the interior of said pressure vessel, the pressure medium being admitted into the interior of the pressure vessel through said intermediate pressure chamber and the connection between said intermediate pressure chamber and the interior of the pressure vessel having at least one constriction of a cross section less than the cross section of the admission of said pressure medium into said intermediate pressure chamber.

BACKGROUND OF THE INVENTION This invention relates to a closure for pressure vessels, particularly autoclaves.

Such closures in the form of a door or resembling a door and comprising two plates jointly slidably movable across the vessel opening and forming a sealed intermediate pressure chamber of slightly variable volumetric capacity between them have already become known in the art. In these known closures the intermediate pressure chamber and the interior of the pressure vessel are in communication and sealing means are provided between the closure and the interior of the pressure vessel.

Such pressure vessels which are fitted with a closure of the above-described kind have the defect that an external pipe must be connected to the closure for the purpose of generating a suitable pressure in the intermediate pressure chamber formed between the two plates. The presence of this pipe prevents the plates from being slidably moved like a sliding door.

Another drawback of the above-described arrangement is that a sufficiently high pressure cannot build up in said intermediate pressure chamber until the pressure in the interior of the pressure vessel has reached a fairly high level. This means that the pressure vessel is not satisfactorily sealed during the initial filling stage.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a closure which avoids all the above-mentioned drawbacks, and which can also be used for large capacity high-pressure vessels, such as autoclaves.

Another object of the present invention is to provide a closure operable in the manner of a sliding door.

A further object of the present invention is to provide a closure in the form of a door capable of being preheated to avoid the creation of major temperature differentials by the pressurized medium inside the pressure vessel.

Yet another object of the present invention is the provision of a closure which will seal the pressure vessel as soon as the operation of filling begins.

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To axtain these objects the present invention proposes a closure for a pressure vessel, particularly an autoclave, having an opening closeable by a door, which comprises an inner and an outer plate jointly slidably movable across the opening of the pressure vessel and forming an intermediate pressure chamber between them, means for sealing said intermediate pressure chamber in relation to the outside, passage means communicating between said intermediate pressure chamber and the interior of said pressure vessel, sealing means provided between the closure and the interior of said pressure vessel, and pipe means for the admission of a pressure medium into said intermediate pressure chamber, the pressure medium being admitted into the interior of the pressure vessel through said intermediate pressure chamber and the passage means between said intermediate pressure chamber and the interior of the pressure vessel having at least one constriction of a cross section less than the cross section of the pipe means for the admission of said pressure medium into said intermediate pressure chamber.

By virtue of this arrangement the pressure inside the intermediate pressure chamber, which has a slightly variable capacity, will immediately build up to a higher level than that in the vessel interior and thus urge the inner plate against the vessel opening to close and tightly seal the vessel interior. Moreover, in view of the fact that when filling a hot medium into the pressure vessel the latter first flows through the intermediate pressure chamber, the closure will be preheated. The provision of expensive pipe means between the intermediate pressure chamber and the vessel interior can be dispensed with, since communication can be provided directly through the inner plate of the door facing the vessel interior.

BRIEF DESCRIPTION OF THE DRAWING Two embodiments of the invention will now be described by way of example and with reference to the accompanying drawing in which:

FIG. 1 is a highly diagrammatic section of an autoclave or high-pressure vessel provided with a closure according to the invention, and

FIG. 2 is a fragmentary section, on a larger scale, of a modification in the construction of the proposed closure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a pressure vessel or autoclave generally indicated by the reference numeral 1. For the sake of clarity the dimensions of the pressure vessel are shown greatly reduced by the omission of portions between fracture lines. A closure generally indicated by the reference numeral 2 forms a pressure-tight seal for the pressure vessel 1. This closure 2 consists of a door indicated generally by the reference numeral 3 and is slidably mounted in slideways 4. This door 3 may be arranged to be slidably raised and lowered or to be moved sideways in the manner of a sliding door. In the latter case the drawing in FIG. 1 should be imagined as being turned over on its side.

The door 3 comprises two relatively spaced plates 7 and 8 which are jointly slidably movable across the opening 5 of the pressure vessel 1, and which enclose an intermediate pressure chamber 6 between them. This intermediate pressure chamber 6 is sealed from the outside and its volumetric capacity is slightly variable by virtue of the two plates 7 and 8 being relatively movable towards and away from each other. In the illustrated embodiment the outer plate 8 remote from the pressure vessel 1 is held between slideways 4 which embrace two edges 8a of this plate 8 so that it is therefore slidable only in the plane containing the plate. The inner plate 7 facing the interior of the pressure vessel 1 can be moved towards and away from the vessel interior. This inner plate 7 is provided with sealing means 9.

According to an essential feature of the invention the admission of a pressurized medium into the pressure vessel 1 is through the intermediate pressure chamber 6 and the connection between this intermediate pressure cham her 6 and the vessel interior has a cross section of flow which is locally less than the cross section of the admission and inlet into the intermediate pressure chamber 6.

Admission into the intermediate pressure chamber 6 is through a pipe 10, a second pipe 11 providing communication between the intermediate pressure chamber 6 and the vessel interior. The inner end of the pipe 11 carries a nozzle 12 having a reduced cross section. According to another feature of the invention the cross section of this nozzle 12 is adjustably variable and the nozzle 12 can be closed if required.

In the embodiment according to FIG. 1 the intermediate pressure chamber 6 is sealed from the outside by a diaphragm 13 which defines one side of said chamber. The edges of the diaphragm 13 are pressed tightly against the plate 7 by clamping rails 15 and screws 14. The pipe 10 communicates with the space formed between the plate 7 and the diaphragm 13. With reference to FIG. 1 it will also be seen that the pipe 11 between the intermediate pressure chamber 6 and the interior of the vessel 1 is located on that side of the vessel which is remote from the outlet end 10a of the pipe 10.

When the vessel 1 is being filled the following conditions arise: Owing to the larger cross section of the admission pipe 10 there is an immediate considerable pressure build-up in the intermediate pressure chamber 6 between the plate 7 and the diaphragm 13 and this pushes the diaphragm 13 against the outer plate 8 which supports it. As the pressure continues to rise the plate 7 and its sealing means 9 are displaced towards the open end of the vessel 1. Meanwhile, the pressure inside the pressure vessel 1 likewise rises. However, since the external face of the plate 7 which is exposed to the pressure is greater in area than that exposed to pressure on the inside, the seal is maintained even when the pressure in the vessel interior has risen to the final full pressure and equals the pressure in the intermediate pressure chamber 6. It is useful during the filling of the vessel 1 to preheat the door 3 and particularly the plate 7, for instance with steam. Entering at the outlet end 10a of pipe 10 the steam will flow across nearly the entire surface of the plate 7 before reaching the inlet end of pipe 11 which is on the side of the pressure vessel 1 remote from the outlet end 10a of pipe 10. The pressure vessel 1 is fitted with an outlet pipe 16 controlled by a valve 17. If desired the steam or like hot gas or vapor, which slightly cools down during preheating the door 3 and particularly the plate 7, can be at least partly exhausted to the outside.

The closure 2 as proposed by the present invention also permits the pressure vessel 1 to be easily opened when the pressure it contains is relieved. For this purpose the invention provides at least one compression spring 18 which generates a thrust opposing an increase of the volumetric capacity of the intermediate pressure chamber 6 when the pressure vessel 1 is being closed. This compression spring 18 is supported on the outside face of the plate 8 facing away from the vessel interior. The illustrated embodiment in FIG. 1 shows the provision of two such springs 18. Each of these springs is interposed between the outside face of the plate 8 and the head 19 of a screw 21 which slidably passes through the plate 8 and in bores 20 and which is screwed into the inner plate 7. These springs 18 which may be slightly precompressed are further compressed when the pressure inside the intermediate pressure chamber 6 rises and the plate 7 is forced further away from plate 8. Conversely these springs 18 operate to retract the plate 7 towards the plate 8 when the pressure inside the intermediate pressure chamber 6 is relieved. This will usually be done when the pressure vessel 1 is to be emptied and the plate 7 will then automatically return into a position in which it allows the door 3 to be easily slidably moved.

It will further be understood by reference to FIG. 1 that the slideways 4 are supported by a frame 22 or the like embracing the vessel 1. This makes for a compact design providing the pressure vessel 1 and its closure 2 forming a self-contained possibly readily portable unit.

As already mention, the means for sealing the intermediate pressure chamber 6 in FIG. 1 is a diaphragm of which the edges are pressed by clamping rails 15 against the inner plate 7 and which is adapted to be supported by the outer plate 8 when deflected. In the slightly modified embodiment according-to FIG. 2 the sealing'means is formed by a bellows 23 which has at least one folding crease and of which the edges 24 and 25 are each secured to one of the plates 7 and 8 in a manner forming a tight seal. The fixing means may again have the form of clamping rails 27 and screws 26. Otherwise this embodiment is functionally and structurally similar to the embodiment described with reference to FIG. 1.

One advantage of the proposed arrangement is that the door 3 can be preheated by steam or the like before the pressure vessel 1 is pressurized. Furthermore, the proposed closure provides a seal between the .door and the pressure vessel 1 which is already established 'when filling begins, since there is an immediate pressure build-up in the intermediate pressure chamber inside the door urging the inner plate 7 into sealing contact with the pressure vessel 1 opening as soon as the pressure medium is admitted and before a substantial volume of medium actually enters the pressure vessel 1. Another advantage afiorded by the invention is that the discharge of the pressure medium from the pressure vessel 1 results in an automatic retraction of the door from the vessel opening permitting the door to be easily slidably moved and opened. The proposed closure is particularly suitable for use on large capacity high-pressure vessels which can usually be closed only by means of sliding doors or gates.

It will be understood that all the features disclosed in the drawing and mentioned in the foregoing description may be separately or jointly included in embodiments of the invention.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present two embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A closure for a pressure vessel, particularly an autoclave, having an opening closeable by a door, comprising:

(a) an inner and an outer plate jointly slidably movable across the opening of the pressure vessel and forming an intermediate pressure chamber between them;

(b) means for sealing said intermediate pressure chamber in relation to the outside;

(0) passage means communicating between said intermediate pressure chamber and the interior of said pressure vessel;

(d) sealing means provided between the closure and the interior of said pressure vessel; and

(e) pipe means for the admission of a pressure medium into said intermediate pressure chamber, the pressure medium being admitted into the interior of the pressure vessel through said intermediate pressure chamber and the passage means between said intermediate pressure chamber and the interior of the pressure vessel having at least one constriction of a cross section less than the cross section of the pipe means for the admission of said pressure medium into said intermediate pressure chamber.

2. A closure as set forth in claim 1, wherein the outer plate is mounted in slideways which partly embrace the edges of said plate, said plate being thus slidably movable exclusively in the plane containing said outer plate.

3. A closure as set forth in claim 2, wherein said slideways form part of a structure at least partly embracing said pressure vessel.

4. A closure as set forth in claim 1, wherein a diaphragm is arranged to seal said intermediate pressure chamber from the outside, said diaphragm being backed by the outer plate, extending across the width of said intermediate pressure chamber and having its edges pressed by clamping rails against said inner plate.

5. A closure as set forth in claim 1, wherein a bellows is arranged to seal said intermediate pressure chamber from the outside, said bellows having at least one folding crease and its edges secured in a sealing manner to one of said two plates.

6. A closure as set forth in claim 1, comprising spring means opposing the increase in volume of said intermediate pressure chamber when said inner plate is urged towards the opening of said pressure vessel.

7. A closure as set forth in claim 6, wherein said spring means are interposed between the outside face of said outer plate and the head of a screw which slidably passes through an opening in said outer plate, and which is screwed into said inner plate.

References Cited UNITED STATES PATENTS 3,352,446 11/1967 Anderson et al. 220-41 3,417,896 12/1968 Loveless 22041 GEORGE T. HALL, Primary Examiner 

